In recent years, in order to increase the luminance of an image display apparatus for color display, a technique attracts attention, which has a configuration including not only three sub-pixels, i.e., a red color sub-pixel displaying red color, a green color sub-pixel displaying green color, and a blue color sub-pixel displaying blue color, but also, for example, a white color sub-pixel displaying white color.
For example, Publication of Japanese Patent No. 4120674 (Patent Document 1) describes an image display apparatus including a liquid crystal panel provided with a display pixel including not only a sub-pixel for color display but also a sub-pixel having a transparent or white color area, an illumination apparatus for illuminating the liquid crystal panel, and an display image conversion circuit for determining an image signal corresponding to a sub-pixel on the basis of an input RGB image signal and a control signal for adjusting the luminance of light emitted from the illumination apparatus.